1. Field of the Invention
The present invention relates to a printing apparatus, an external apparatus, a printing system and a control method for the printing apparatus.
2. Description of the Related Art
There is a technique in which an image processing apparatus such as a printing apparatus receives “one copy” worth of data in page order from a document server and temporarily stores the data, and if printing of a plurality of copies is required, the stored data is repeatedly used and output. Also, in the case of collation printing, there is a technique in which stored data is used to perform collation and output, and if double-sided printing is required, data is acquired from the stored data in the print order and output. Here, “collation printing” refers to a configuration in which data is collated and printed in a page order such as 1-2-3, 1-2-3 when printing of a plurality of copies has been specified.
There is also a technique when printing a plurality of copies in which data is transmitted from the document server to the image processing apparatus as many times as the number of copies to be printed, and if collation printing is required, data is collated in the document server and transmitted to the image processing apparatus.
With the above technique, constantly sending data from the server over a number of times equating to the specified number of copies when collation printing a plurality of copies takes extra time for data transmission. Even in the case where the collation is performed by the image processing apparatus, the collation function may not always be available in the image processing apparatus, depending on the size of the document to be output or the like.
In view of this, a technique has been proposed for changing the method by which images are transmitted from an external apparatus according to the remaining area of a storage apparatus in a connected image processing apparatus, and using a collation function that depends on the changed transmission method (see Japanese Patent Laid-Open No. 2005-78490).
However, with this technique, image transmission switching is performed based on the remaining area of the storage apparatus at the start of printing, which means that printing may have to be discontinued if the capacity of the internal storage apparatus proves insufficient during printing. Further, while the image transmission method needs to be changed depending also on the type of print job to be executed, the above technique does not allow for this.